1. Field of the Invention
The present invention relates to floorboard, and more particularly, to a flooring panel assembly having mechanical coupling elements, which is mounted to the floors of buildings, etc.
2. Description of the Related Art
In general, flooring panels are used to decorate the floors of buildings. Although flooring panels made of synthetic resins have conventionally been used, flooring panels made of wood are increasingly used in recent years to provide a more aesthetically pleasing appearance and excellent functions.
There is known a wood flooring panel, which is configured in such a manner that a fastening structure is provided at a long or short side of the flooring panel to ensure that opposite sides of neighboring flooring panels are assembled with each other, in order to assure easy assembly between flooring panels and consequently, enhanced construction efficiency.
FIG. 1 is a view illustrating an assembly relationship between two flooring panels of a conventional floorboard.
Specifically, as illustrated in FIG. 1, in the case of the conventional floorboard, a first flooring panel 1 and a second flooring panel 2 are assembled with each other as a tongue part 20 of the second flooring panel 2 is coupled with a recessed part 10 of the first flooring panel 1. To this end, the tongue part 20 is first horizontally introduced into the recessed part 10 and then, is pivotally rotated downward by a predetermined angle about a pivot point A.
More particularly, the tongue part 20 is introduced into the recessed part 10 in a substantially horizontal direction until a tip protruding portion 21 of the tongue part 20 is fitted into a recess 11 of the recessed part 10 and at this time, the tongue part 20 comes into contact with the recessed part 10 at the pivot point A.
The tongue part 20 includes a retaining portion 22, which protrudes downward by a predetermined length. Also, when the tongue part 20 is introduced into the recessed part 10, an upper lip 15 of the recessed part 10 and a front surface portion 25 of the tongue part 20 come into contact with each other at a point. This contact point is the pivot point A.
If the tongue part 20 is rotated along an arc B designated by a dotted line in FIG. 1 about the pivot point A, the retaining portion 22 of the tongue part 20 is fitted into and seated in a retaining recess 13 of the recessed part 10 to ensure coupling between the tongue part 20 and the recessed part 10.
That is, the tongue part 20 is coupled with the recessed part 10 as it is pivotally rotated along the arc B about the pivot point A.
However, in the above described coupling manner, to prevent an inner wall 12a of a raised portion 12 provided at an end of the recessed part 10 from hindering rotation of an outer wall 22a of the retaining portion 22 when the outer wall 22a of the retaining portion 22 is pivotally rotated and inserted into the retaining recess 13 along the arc B, the inner wall 12a of the protrusion 12 must be configured such that an angle C between the inner wall 12a and a horizontal plane has a gentle gradient.
In other words, if the angle C has a steep gradient, the outer wall 22a of the retaining portion 22 may fail to pass the inner wall 12a of the raised portion 12, thus making coupling of the tongue part 20 difficult and also, it is necessary to apply sufficient external force to interference-fit the retaining portion 22 of the tongue part 20 to the raised portion 12 of the recessed part 10 when the tongue part 20 is coupled with the recessed part 10, which causes damage to the flooring panels and makes it difficult to assemble the flooring panels.
However, the gentle gradient angle C of the protrusion 12 problematically provides weak coupling force in a horizontal direction even if the tongue part 20 is coupled with the recessed part 10.
In the case where the above described coupling structure is applied to a modern heating system using a heating element (e.g., an electric film or an electric panel) in a simplified construction manner, moreover, a constituent material of a floorboard (conventionally, plywood, Particle Board (PB), Medium Density Fiberboard (MDF), High Density Fiberboard (HDF), etc.) may be severely contracted or expanded due to rapid temperature increase generated when the heating system installed beneath the floorboard is turned on, thereby causing expansion of the recessed part 10, and especially, causing the raised portion 12 to be severely deformed to a state designated by reference numeral 12-1 as illustrated in FIG. 1. This may cause the outer wall 22a of the retaining portion 22 to be separated from the inner wall 12a of the raised portion 12, resulting in an unwanted separation of two flooring panels.